Suitability evaluation method for developing underground coal gasification engineering by utilizing deep coal seam

Abstract

Disclosed is a suitability evaluation method for developing underground coal gasification (UCG) engineering by utilizing a deep coal seam, including: acquiring basic geological conditions, engineering geological problems, hydrogeological conditions, contained coal quality, deep coal seam conditions, and heat and syngas components of unit coal gasification in a deep coal seam region to obtain scores of corresponding influencing factors; determining impact indexes of the geological condition and influencing factors; and determining the suitability of developing UCG engineering by utilizing the deep coal seam according to a comprehensive impact index. The suitability of developing UCG engineering by utilizing the deep coal seam is evaluated by a comprehensive analysis method.

1 . A suitability evaluation method for developing underground coal gasification (UCG) engineering by utilizing a deep coal seam, comprising:
 acquiring basic geological conditions, engineering geological problems, hydrogeological conditions, contained coal quality, deep coal seam conditions, and heat and syngas components of unit coal gasification in a deep coal seam region, and comparing with evaluation criteria of influencing factors of the basic geological conditions, engineering geological problems, hydrogeological conditions, contained coal quality, deep coal seam conditions, and heat and syngas components of unit coal gasification in the deep coal seam region to obtain scores of corresponding influencing factors;   determining impact indexes of a geological condition and engineering geological influencing factor, a hydrogeological condition influencing factor, a coal quality influencing factor, a coal seam condition influencing factor and an influencing factor of heat and syngas components of unit coal gasification according to scores of various influencing factors of the deep coal seam; and   calculating a comprehensive impact index based on the impact indexes of the various influencing factors of the deep coal seam, and determining the suitability of developing UCG engineering by utilizing a deep coal seam according to the comprehensive impact index.   
     
     
         2 . The suitability evaluation method of developing UCG engineering by utilizing a deep coal seam according to  claim 1 , wherein the impact index is specifically as follows: 
       
         
           
             
               
 
               
                 Q 
                 = 
                 
                   
                     ∑ 
                     
                       i 
                       = 
                       1 
                     
                     n 
                   
                   
                     
                       M 
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                         ∑ 
                         
                           i 
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                         n 
                       
                       
                         M 
                         imax 
                       
                     
                   
                 
               
             
           
         
         wherein n is the number of impact factors corresponding to the influencing factors, M i  is a score value of an i th  impact factor of the influencing factor, and M imax  is a maximum score value of the i th  impact factor of the influencing factor. 
       
     
     
         3 . The suitability evaluation method of developing UCG engineering by utilizing a deep coal seam according to  claim 1 , wherein the determining an impact index of a geological condition and engineering geological influencing factor according to scores of various influencing factors of the deep coal seam is specifically as follows: 
       
         
           
             
               
 
               
                 
                   Q 
                   1 
                 
                 = 
                 
                   
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                       i 
                       = 
                       1 
                     
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                         imax 
                       
                     
                   
                 
               
             
           
         
         wherein Q 1  is a result of the geological condition and engineering geological influencing factor, n is the number of impact factors corresponding to the influencing factors, U i  is a score value of an i th  impact factor of the geological condition and engineering geological influencing factor, and U i , is a maximum score value of the i th  impact factor of the geological condition and engineering geological influencing factor. 
       
     
     
         4 . The suitability evaluation method for developing UCG engineering by utilizing a deep coal seam according to  claim 1 , wherein the determining an impact index of a hydrogeological condition influencing factor according to scores of various influencing factors of the deep coal seam is specifically as follows: 
       
         
           
             
               
 
               
                 
                   Q 
                   2 
                 
                 = 
                 
                   
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                       i 
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                       1 
                     
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                         V 
                         imax 
                       
                     
                   
                 
               
             
           
         
         wherein Q 2  is a result of the hydrogeological condition influencing factor, n is the number of impact factors corresponding to the influencing factors, V i  is a score value of an i th  impact factor of the hydrogeological condition influencing factor, and V imax  is a maximum score value of the i th  impact factor of the hydrogeological condition influencing factor. 
       
     
     
         5 . The suitability evaluation method for developing UCG engineering by utilizing a deep coal seam according to  claim 1 , wherein the determining an impact index of a coal quality influencing factor according to scores of various influencing factors of the deep coal seam is specifically as follows: 
       
         
           
             
               
 
               
                 
                   Q 
                   3 
                 
                 = 
                 
                   
                     ∑ 
                     
                       i 
                       = 
                       1 
                     
                     n 
                   
                   
                     
                       W 
                       i 
                     
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                         ∑ 
                         
                           i 
                           = 
                           1 
                         
                         n 
                       
                       
                         W 
                         imax 
                       
                     
                   
                 
               
             
           
         
         wherein Q 3  is a result of the coal quality influencing factor, n is the number of impact factors corresponding to the influencing factors, W i  is a score value of an i th  impact factor of the coal quality influencing factor, and W imax  is a maximum score value of the i th  impact factor of the coal quality influencing factor. 
       
     
     
         6 . The suitability evaluation method for developing UCG engineering by utilizing a deep coal seam according to  claim 1 , wherein the determining an impact index of a coal seam condition influencing factor according to scores of various influencing factors of the deep coal seam is specifically as follows: 
       
         
           
             
               
 
               
                 
                   Q 
                   4 
                 
                 = 
                 
                   
                     ∑ 
                     
                       i 
                       = 
                       1 
                     
                     n 
                   
                   
                     
                       X 
                       i 
                     
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                         ∑ 
                         
                           i 
                           = 
                           1 
                         
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                         X 
                         imax 
                       
                     
                   
                 
               
             
           
         
         wherein Q 4  is a result of the coal seam condition influencing factor, n is the number of impact factors corresponding to the influencing factor, X i  is a score value of an i th  impact factor of the coal seam condition influencing factor, and X imax  is a maximum score value of the i th  impact factor of the coal seam condition influencing factor. 
       
     
     
         7 . The suitability evaluation method for developing UCG engineering by utilizing a deep coal seam according to  claim 1 , wherein the determining an impact index of an influencing factor of heat and syngas components of unit coal gasification according to scores of various influencing factors of the deep coal seam is specifically as follows: 
       
         
           
             
               
 
               
                 
                   Q 
                   5 
                 
                 = 
                 
                   
                     ∑ 
                     
                       i 
                       = 
                       1 
                     
                     n 
                   
                   
                     
                       Z 
                       i 
                     
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                           i 
                           = 
                           1 
                         
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                         Z 
                         imax 
                       
                     
                   
                 
               
             
           
         
         wherein Q 5  is a result of the influencing factor of heat and syngas components of unit coal gasification, n is the number of impact factors corresponding to the influencing factor, Z i  is a score value of an i th  impact factor of the influencing factor of heat and syngas components of unit coal gasification, and Z imax  is a maximum score value of the i th  impact factor of the influencing factor of heat and syngas components of unit coal gasification. 
       
     
     
         8 . The suitability evaluation method for developing UCG engineering by utilizing a deep coal seam according to  claim 1 , wherein the calculating a comprehensive impact index based on the impact indexes of the various influencing factors of the deep coal seam specifically comprises:
 acquiring the impact indexes of the various influencing factors of the deep coal seam, and recording the calculated results as Q 1 , Q 2 , Q 3 , Q 4  and Q 5  according to the sequence of the geological condition and engineering geological influencing factor, the hydrogeological condition influencing factor, the coal quality influencing factor, the coal seam condition influencing factor and the influencing factor of heat and syngas components of unit coal gasification; and   determining the calculated comprehensive impact index Q=Min {Q 1 , Q 2 , Q 3 , Q 4 , Q 5 }.   
     
     
         9 . The suitability evaluation method for developing UCG engineering by utilizing a deep coal seam according to  claim 1 , wherein the determining the suitability of developing UCG engineering by utilizing the deep coal seam according to the comprehensive impact index specifically comprises:
 comparing the comprehensive impact index with a comprehensive impact index corresponding to a preset suitability grade; and   determining the suitability of developing UCG engineering by utilizing the deep coal seam according to comparison results.   
     
     
         10 . The suitability evaluation method for developing UCG engineering by utilizing deep coal seams according to  claim 9 , wherein the suitability of developing UCG engineering by utilizing the deep coal seam is determined by comparing a numerical minimum comprehensive impact index with the comprehensive impact index corresponding to the preset suitability grade.